Command will return error now.

Author: cwahbong

commands/command.go

@@ -1,11 +1,11 @@
 package commands
 
 import (
+	"errors"
 	"fmt"
-	"os"
 )
 
-type Command func(args []string)
+type Command func(args []string) error
 
 func CommandFunc(cmd string) Command {
 	switch cmd {
@@ -22,7 +22,7 @@ func Empty() {
 }
 
 func badCommand(cmd string) Command {
-	return func(args []string) {
-		fmt.Fprintf(os.Stderr, "Command \"%s\" does not exists, see \"jg help\" for more information.\n", cmd)
+	return func(args []string) error {
+		return errors.New(fmt.Sprintf(`Command "%s" does not exists, see "jg help" for more information.`, cmd))
 	}
 }

commands/help.go

@@ -1,9 +1,10 @@
 package commands
 
 import (
+	"errors"
 	"fmt"
 )
 
-func jgHelp(argstrs []string) {
-	fmt.Println("Not implemented yet.")
+func jgHelp(argstrs []string) error {
+	return errors.New(fmt.Sprint("Not implemented yet."))
 }

commands/server.go

@@ -18,7 +18,7 @@ type serverArgs struct {
 	StaticFilePath string
 }
 
-func jgServer(argstrs []string) {
+func jgServer(argstrs []string) error {
 	var args serverArgs
 	flagSet := flag.NewFlagSet("jg-server", flag.ExitOnError)
 	flagSet.UintVar(&args.Port, "p", defaultPort, "Specify the port.")
@@ -30,4 +30,5 @@ func jgServer(argstrs []string) {
 		Handler: backend.ServeMux(args.StaticFilePath),
 	}
 	log.Fatal(server.ListenAndServe())
+	return nil
 }

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"github.com/cwahbong/jg/commands"
 	"os"
 )
@@ -9,6 +10,9 @@ func main() {
 	if len(os.Args) <= 1 {
 		commands.Empty()
 	} else {
-		commands.CommandFunc(os.Args[1])(os.Args[2:])
+		err := commands.CommandFunc(os.Args[1])(os.Args[2:])
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error: %s\n", err.Error())
+		}
 	}
 }